Miscellany » The People of the Book

1. The ceremonial cleanliness of the People of the Book (Jews and Christians), and whether it is desirable to avoid [coming into contact with] them:
"As for the People of the Book, it is widely believed that they are najis. However, it is likely that they are tahir, though, ihtiyat should be adhered to". Masaa’il, article 82.